Cross chain



109mg A H. ST. PIERRE CROS S CHAIN Filed May 8, 1936 effe Patented Feb.22, 1938 UNITED STATES 10ans ATENT FFICE 4 Claims.

The principal objects of this invention are to provide a cross chainwith an extra amount of surface on the ground contacting side thereofand with cups on said side for providing a better grip on the ground andin some cases suction resistance; to provide flattened surfaces on therear which prevent the digging of the chain into the tire and reduce thedepth of the chain; to provide the case hardening on a surface of such anature that the chain will wear very much longer than has been the caseheretofore before the part that is case hardened is worn away, and toprovide a chain which will have all these properties and yet will beeasy to manufacture and involve no increase in expense corresponding tothe advantages obtained.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying zo drawing, in which Fig. 1is a plan of a cross chain constructed in accordance with thisinvention, with parts broken away;

Fig. 2 is a side view or edge view of the same;

l5 Fig. 3 is a sectional view on the line 3--3 of Fig. 1;

Fig. 4 is a sectional view on the line 4-4 of Fig. 1 on enlarged scale,and

Fig. 5 is a plan like Fig. 1 of a modified con- 30 struction.

It has been the practice heretofore to make chains of wire andcase-harden them, which results in a case-hardened section on theoutside surfaces which, when worn through, leaves the 35 chain with nohardened material that very effectively avoids wear. Various shapes ofchains have been made with the links formed of a piece of Wire weldedtogether and they have all been subjected to the above difficulty.

40 In the form shown in Figs. l, 2, 3 and 4 each link Il] of the chain,which is the subject of this invention, is formed of a peculiar shape inwhich on both sides is a cup ll, which are shown as oblong and which, inFig. 5, are shown at l2 as i5 circular. Their cuter surfaces are in thesame plane and two of them are located on each link at opposite sidesand opposite ends.

From an inspection of Figs. 3 and 4 it will be seen that the area I3which is case-hardened has 50 two thicknesses of case-hardening at Hland l5 on each side and each end of the elongated cup Il so that thewear will be more slow than in the case of a single layer ofcase-hardening. Until the chain is worn down to the bottom I6 of 55 thecup there are always transverse case-hardening surfaces on the chain tobear on the ground and retard wear. When the wear gets down to thebottom of the cup there will still be a flat wide horizontal surface i6for it to wear through before the soft inside part of the link isbrought 5 into contact with the ground.

This situation applies to Fig. 5 in the same way and the details thereofneed not be explained therefore. Of course, the case-hardening extendsthroughout the surface of the link. The 10 bottom of the link isflattened out at I1 so that fiat surfaces ll only bear on the tire andtherefore cannot dig into the tire and injure it, at least until after avery long amount of wear. Infact, no wear appears on the tire untilafter many of 15 these chains have been used and discarded. 'Ihen it isnot likely to take place at the same places so that it can almost bedisregarded.

The shape of each link involves the cups ll or l2 on the opposite sidesof the wearing surface 20 and arms I8 extending in opposite directionsfrom these cups fiat on the tire. Each of these arms IB is connectedwith the next cut Il or I2 by a slanting arm i9. These links are made inquantities all alike and every alternate one is made open and thenWelded. Half of them do not have to be welded.

It will be seen that the outer wearing surface is almost fiat butinterrupted while the inner wearing surfaces are almost flat and almostcontinuous. This constitutes a very strong chain and a long wearing onewhich adds very materially to its utility in practice and to the life ofthe tire. It does not involve much additional expense and not any inproportion to its additional durability.

Having thus described my invention and the advantages thereof, I do notwish to be limited to the details herein disclosed, otherwise than asset forth in the claims, but what I claim isz- .1.. A cross chain linkcomprising a pair of cups on the ground engaging surface of the link, anarm extending in opposite slanting directions from each cup andconstituting the tire engaging surface, said arms being flattened toprevent wear on the tire, and arms connecting the rst named arms to theopposite cup.

2. As an article of manufacture, a chain link having a flat outersurface provided with two parallel elongated depressed cups on oppositesides and at opposite ends of said surface, said surface being in thegeneral shape of a parallelogram with said cups at the obtuse anglesthereof.

3. As an article of manufacture, a chain link having a generally flatouter surface provided with two parallel depressed cups on oppositesides and at opposite ends of said surface, said surface being in thegeneral shape of a parallelogram with said cups at the obtuse anglesthereof, and the link projecting inwardly from said surface toward thetire and having a generally convex rear surface, flattened at the rearof the acute angles of said parallelogram.

4. As an article of manufacture, a cross chain formed of links, eachlink having integral cups, the edges thereof constituting a groundengaging surface, said cups having their external surface longer on theground engaging half of the link than on the other half.

HENRY ST. PIERRE.

